1. Field of the Invention
The present invention relates to a manufacturing method in which a rare-earth oxide can be sintered at low temperature.
2. Description of Prior Art
As a common ceramic, alumina (Al2O3) or zirconia (ZrO2) have been used. Although there is known amorphous formation, single-crystal growth and thin-film formation as the formation method, sintering is the most common method. Also, in order to easily complete sintering, a sintering aid is used.
The present inventors have paid attention to boron oxide (B2O3) as a sintering aid. Patent Document 1 and Non-patent Document 1 can be listed as a prior art material in which boron oxide (B2O3) is used as a sintering aid.
Patent Document 1 has disclosed that yttria (Y2O3) powder is formed by cold isostatical press (CIP), the formed body is fired at 1400-1800° C., cooled, and thereafter heated at 1400-2000° C. in the presence of a boron compound (B2O3), so that a dense yttria (Y2O3) sintered body can be obtained. According to Patent Document 1, it is assumed that the dense sintered body can be obtained because the presence of a boron compound promotes sintering due to diffusion of B2O3 inside the body.
Non-patent Document 1 has disclosed that yttria (Y2O3) powder is formed by CIP (140 MPa), first sintering is performed to the formed body at 1400-1700° C., BN is sprayed on the sintered body, and second sintering is performed by HIP (140 MPa, 1400-1700° C.), so that an yttria (Y2O3) sintered body having excellent transparency can be obtained.
Patent Document 1: Japanese Patent Application Publication No. 2000-239065
Non-patent Document 1: Production of Transparent Yttrium Oxide by HIP sintering, The Ceramic Society of Japan, 2004, Preprint 2G09
However, according to these documents, firing at relatively high temperature such as 1700-2000° C. is required to obtain a sintered body having small porosity, or a complicated manufacturing process such as HIP processing after first sintering is required to obtain a sintered body.
The object of the present invention is to provide a rare-earth oxide sintered body and a corrosion-resistance material having high density and excellent plasma-resistance which can be manufactured easily at low temperature, and a manufacturing method thereof.